Amperometric arrays in flowing solution analysis

The design and evaluation of flow-cell geometries for application to solution analysis utilizing an array of independently controlled electrodes in conjunction with amperometry is discussed. The optimization and performance testing of a circular array of glassy carbon disc electrodes in a wall-jet arrangement is presented. The array is shown to behave as planar electrodes or thin-layer electrodes depending upon whether or not the hydrodynamic boundary layer is unrestricted or restricted. A novel array of platinum-on-copper electrodes, arranged in a planar spiral, is used to demonstrate anomalous behaviour due to reflection effects at the outer extremes of the flow-cell volume. The difficulty in maintaining potentiostatic control of a linear array of glassy carbon disc electrodes in a thin-layer slot design is discussed in terms of ohmic drop.